<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>数组！</title>
		<script>
			var ar=new Array(10);
			ar[0]="老刘";
			ar[1]="蛋妞";
			ar[20]="龙凯";
			alert(ar.length);
			var str=ar.join("#");
			alert(str);
			ar.length=6;
			alert(ar.join("#"));
			ar.push("大牛");
			ar.unshift("老李");
			alert(ar.join("#"));
			ar.reverse();
			alert(ar.join("#"));
			
			alert(ar.includes("老刘"));
		</script>
	</head>
	<body>
	</body>
</html>